Business, educational and other types of presentations typically utilize a combination of recorded audio and either still frame images or video. Recording and playback of video involves significantly more data than is typically required in recording and playback of audio. Consequently, recording and playback of a video presentations requires significantly higher bandwidth, processing power and memory storage space.
In the prior art, as an alternative to using video, audio presentations have been combined with still frame images. Since still frame images involve significantly less data than video, presentations utilizing the combination of audio and still frame images require significantly less processing power and storage capacity than video presentations. However, synchronization of still frame images with particular portions of the audio track in a presentation is problematic. Typically, in order to switch at the correct time from the display of one still frame image to the display of the next still frame image, it is required that a person either manually change a slide or transparency, or that the person actuate a user interface of the computer or presentation device in order to change the still frame image.
Another associated problem relates to recording primarily-vocal presentations where there are illustrations, slides or other visual aids. Audio recording of such a presentation does not provide the benefit of recording the visual components of the presentation. As discussed above, video recording of the presentation has the disadvantage of requiring significantly more bandwidth, processing power and storage capacity than simply audio recording the presentation. Previous solutions to this problem have included recording the audio portion of the presentation with a cassette recorder, while taking still frame images or pictures of the visual portions of the presentation with a camera. Then, it must be determined at a later time which pictures correspond to which portions of the audio recording.
Some digital cameras include audio recording capabilities. However, these digital cameras are limited in capability to adding a short audio annotation to an individual picture. This one-to-one relationship between a short audio annotation and a single still frame image is not an efficient or convenient format for creating or recording presentations or lectures.
A digital audio recording device is an audio recorder that receives sound waves and provides in response a digital data stream. The digital audio recording device of the invention also includes an image recorder which provides digital representations of multiple still frame images. A synchronizer receives the digital audio data stream and the digital representations of the still frame images and provides as an output the digital audio data stream synchronized with the still frame images. An image selection input provides interactive synchronization of particular still frame images with particular portions of the audio data stream. In addition, methods of synchronizing the audio data stream and the still frame images are provided.